JavaScript Playground
Run JavaScript code online with instant output and console logs.
What does JavaScript Playground do?
JavaScript Playground lets you write and execute JavaScript code directly in your browser. Captures console.log, warn, error, and info output with proper formatting. Includes error messages with details and execution time tracking. Supports arbitrary JS including loops, functions, and objects.
Use Cases
- •Quickly testing JavaScript code snippets
- •Learning and experimenting with JavaScript concepts
- •Debugging logic before adding to a project
- •Demonstrating code to colleagues or students
- •Validating algorithms and data transformations
How to Use
- 1Write or paste JavaScript code in the left panel
- 2Click the Run button (or use the shortcut)
- 3View console output in the right panel
- 4See execution time displayed after each run
- 5Error messages appear in red with details
Frequently Asked Questions
Is my code sent to a server?
No. All code execution happens entirely in your browser using the Function constructor. Your code never leaves your device.
What features are supported?
The playground supports standard JavaScript including console.log/warn/error/info, loops, functions, classes, Promises (basic), and ES6+ syntax supported by your browser.
Is there a time limit?
Yes. Execution is limited to 5 seconds to prevent infinite loops from freezing your browser. The timeout message will appear if exceeded.